The field of the invention is system and methods for x-ray imaging. More particularly, the invention relates to systems and methods for estimating a map of noise statistics in data acquired with an x-ray imaging system such that the noise map can be implemented to account for noise during an iterative image reconstruction.
Iterative image reconstructions, including both algebraic reconstruction and statistical image reconstruction frameworks, have been used for reconstructing high quality tomographic images from severely noise contaminated projection data. It has been known that a statistical weight is critical for great image quality; however, using existing methods for producing noise maps, the data acquisition process must be repeated many times to obtain a good estimate of the statistical noise. This has been a bottleneck for image quality improvement, especially when balanced against the desire to reduce x-ray radiation dose.
It would therefore be desirable to provide a system or method for estimating a statistical noise map that does not require multiple data acquisitions that result in a higher x-ray dose exposure to the imaged subject.